An estimated 26 million U.S. adults have chronic kidney disease, according to the National Kidney Foundation. Diabetes, high blood pressure and family history are the leading risk factors. Doctors use urinalysis, blood tests, ultrasounds, X-rays and biopsies to help diagnose kidney disease and conditions leading to renal insufficiency. Early detection and treatment can often keep kidney insufficiency from escalating to acute kidney failure.
Renal System Overview
Your renal system consists of two kidneys, the bladder, ureters, and the urethra. The ureters are tubes that deliver urine from the kidneys to the bladder, which holds urine until it is released through the urethra tube. The kidneys remove waste products and drugs, balance body fluid levels, control red blood cell production, produce a form of Vitamin D and release blood pressure-regulating hormones. These fist-size organs filter about 200 quarts of fluid every 24 hours.
Renal Insufficiency -- Stages 1 and 2
Renal insufficiency occurs when when the kidneys' filtration abilities diminish. Doctors use a glomerular filtration rate to define kidneys' effectiveness in filtering blood and removing waste. This GFR is calculated using serum creatinine value, along with age, gender, body size and race. Creatinine is a chemical molecule in blood that is filtered by the kidneys and measured by a blood test.
The National Kidney Foundation has established five stages of kidney disease and insufficiency. Stage 1 consists of minimal kidney disease, with a GFR of 90 percent or better. Stage 2 indicates mild kidney disease and a GFR range of 60 percent to 89 percent.
Patient might experience none or few symptoms during early stages. Early-stage renal insufficiency is treated with dietary changes such as a lower protein diet. Patients' doctors monitor their diseases and might prescribe medications to treat any contributing factors such as high blood pressure and diabetes.
Advanced Chronic Renal Insufficiency -- Stages 3 and 4
Stages 3 and 4 herald an escalating insufficiency. GFR ranges from 30 percent to 59 percent in Stage 3, and from 15 percent to 29 percent in Stage 4.
Patients in these stages can experience high blood pressure, fatigue, eye puffiness, hand and feet swelling and lower back pain. The color, amount and frequency of urine might change.
Doctor sometimes place these patients on a high-calorie diet low in protein, potassium, sodium and phosphorus. They might prescribe high blood pressure medications, drugs, and supplements such as calcium.
Acute Renal Failure -- Stage 5
Patients with a GFR of less than 15 percent are in Stage 5, end-stage renal failure. Kidney failure for them might occur over a few hours or days, and it is characterized by an acute loss of the kidneys' ability to filter blood and eliminate waste products. Certain conditions, including advanced age, heart failure, liver disease, and blood vessel blockages, increase risk for acute renal failure.
Symptoms include anemia, headache, drowsiness and weakness, lowered mental alertness, thirst, muscle cramps, diarrhea, itchy skin and eyes, night-time urination, skin tone changes, increased swelling, urine output changes, high blood pressure, poor digestion or difficulty breathing.
Acute renal failure is treated with hemo-dialysis or peritoneal dialysis at home or in a hospital or clinic. Dialysis uses chemicals and machinery to replicate the functions of your kidneys. A kidney transplant can replace one or both damaged kidneys.
Untreated failure can lead to death. However, acute failure can be reversed with successful resolution of the underlying condition leading to failure.